An up-to-date summary of COVID-19 vaccines. OP-ED by Ala Tocarciuc


Certain quantities are also expected to be delivered to small countries through international vaccine alliances. The principle of equality in access must be respected. I want to believe that in mid-2021 we could receive a certain amount of the vaccine that will obtain authorization and will prove to be safe and effective in Moldova…”

Earlier this week, the American company Moderna announced preliminary results about its own anti-Covid vaccine. It has proven to be effective, providing 94.5% immunity.

A day after they announced that their vaccine is highly effective in preventing Covid-19, Moderna said European regulators have begun a rolling continuous review of the product for approval.

Several news reports establish Modern's RNA-1273 vaccine as one of the first potentially authorized Covid-19 vaccines on both sides of the Atlantic.

Their rivals Pfizer and BioNTech conducted the final efficacy analysis for their Covid-19 Phase III study, and the final results confirm the release of last week's title: their vaccine is 95% effective in preventing Covid-19.

They also said that the vaccine was 94.5% effective in older adults, adhering to concerns that the first Covid-19 vaccines might not work as well in one of the populations most susceptible to severe disease.

The two companies said they had also exceeded the FDA's key two-month tracking safety threshold and will file an emergency use permit "within days".

None of the companies have yet submitted the files to the U.S. agency.

Being the second company to release essential data about a vaccine, Moderna is the third to begin a continuous rolling review at the EMA. AstraZeneca and BioNTech, both based in Europe, announced in early October that regulators had begun a continuous rolling review of vaccine dossiers. Moderna said they filed documents with the EMA on October 14.

Chinese biotech company Sinovac on Wednesday published results evaluated by colleagues for its candidate for the COVID-19 CoronaVac vaccine, with data showing that the vaccine triggered a 90% rapid immune response in patients. But the same data also illustrated that the level of antibodies produced was lower than those who recovered from the disease.

There are currently more than 300 COVID-19 vaccines in the research phase, 11 of which are now in the third phase of clinical testing.

These headlines give us high hopes for an effective vaccine against COVID-19. So far there has been a lot of complaints, that no immunity is formed, their antibody titer is low, that there will be no effective vaccine against COVID-19.  The announcements of the last few days have dispelled definitely these speculations.  We are now convinced that it is possible to have a vaccine with a very good efficiency of 95 per cent.

On the other hand, this news also has adverse effects, i.e., it contributes to the creation of euphoria and false illusions, such as that the pandemic is coming to an end. Some people only read news headlines and don't come in.

The risk that people could abandon protective measures increases significantly in these conditions.

I think it is appropriate to interpret the messages correctly and point out some important moments.

The development of the vaccine against COVID_19 is now done on the basis of 4 different technologies.

Moderna, Pfizer and BionTech are developing the vaccine based on an absolutely new technology for vaccines. Until now, this technology has been used in the development of drugs for genetic disorders, but it has never been used to produce vaccines.

The technology is called mRNA – message on a chain of ribonucleic acids. The RNA chain serves as a carrier of genetic messages. The chain is inserted into the human body, and it must reach the cells in the immune system of the human body and send them the message "please produce antibodies to this COVID-19", taking the antigen model into the message.   Thus, the human body begins to produce antibodies to the antigen COVID-19.

In the case of vaccines, the carrier may be an RNA chain or an adenovirus vector. On the adenovirus vector the same encodes a message, it enters the body, transmits the message and the body begins to produce antibodies. The Russian vaccine (human adenovirus) and the English vaccine (monkey adenovirus) were developed on the vector model.

The Chinese vaccine has been described as an old one, using a chemically inactivated virus in the hope of creating a protective antibody response. Russia is also developing a vaccine based on this technology.

It should be noted that for Phase Three studies, companies usually enroll at least 30,000 participants. Of this total, about 25% receive placebo and the remaining 75% – the vaccine tested. In a clinical trial it is very important that the enrolled people are of different ages and ethnicities.  

What do these 90 to 95% figures tell us?  

This means that in 90-95% of those who received the vaccine, it worked. We don't yet know all the data from the studies, but we do know that at least 9 out of 10 have developed immunity, which has shattered all the myths that there will be no vaccine capable of generating this immunity.

In the case of the development of the COVID-19 vaccine, the protocol was widely discussed with the FDA and thus a generalized clinical protocol was approved, where a minimum set of criteria was established to be carried out by all companies producing vaccines so that they could subsequently be evaluated for authorization. In this protocol it is written that immunity must reach a certain value at the period of two months.  Safety data for all these vaccines are collected 2 months after the last dose administered. The two-month program is strategic that the vaccine can be included in the emergency assessment procedure.

When could we have a new vaccine here in the Republic of Moldova?

In order to expedite the procedures for authorizing vaccines against COVID-19, the procedures have been modified at both the FDA and the EMA. A new model of procedure, called “rolling submission", has been established, meaning that a company may apply to the authority’s parts of the file that they have available at that time and not when the whole file is ready, which allows to save time. Subsequent parts apply according to an agreed schedule

From the news we know that Moderna and Pfizer intend to apply the dossier to the FDA, now in November. The FDA said it would review all files as a matter of urgency and issue an   emergency authorization, then possibly in the spring they will also issue a full authorization, when safety data will also be analyzed. A vaccine must be effective and safe.

In the happiest scenario, in the first quarter of 2021 the first manufacturing companies could get authorization from the FDA or/and EMA. It is known from specialized sources that most companies also produce bulk in parallel, so that when they obtain the authorization, they can dose, pack and deliver the vaccine in fast terms.

Providing anti-COVID vaccine is not only a medical problem, but also a political one. There has already been a lot of talk about inequality and cannibalism- because large countries have secured stocks for them, leaving smaller and poorer countries uncovered.

Certain quantities are also expected to be delivered to small countries through international vaccine alliances. The principle of equality in access must be respected. I want to believe that in mid-2021 we could receive a certain amount of the vaccine that will obtain authorization and will prove to be safe and effective in Moldova.